The present invention is directed to a blower housing. More specifically, the present invention is directed to a blower housing for use as part of a blower assembly used in furnaces to remove combustion gases and can be easily mounted to a furnace collector box for flue exhaust transitions.
The need to heat structures to control the interior temperature has been a requirement for modern housing for a long time. One of the current popular methods used to heat""structures is with a furnace that burns either oil or natural gas. Due to the increasing costs of fossil fuels, the operating efficiency of furnaces has become a greater and greater concern.
One common method of increasing the fuel efficiency of the burner within a furnace has been to utilize a blower to induce a draft through the furnace to draw the heated air and the products of combustion through a heat exchanger and exhaust them through an exhaust pipe. The blower increases the draft such that the heated air and the products of combustion can travel through as tortured a path as possible to increase the amount of heat removed from exhaust gases within the heat exchanger. The increase in the flow of air thereby increases the heat transfer and generating capacity of the burner while simultaneously using less fuel per BTU of heat generated. The addition of a blower motor to a furnace generates a rating of about 80 percent fuel efficiency in a modern furnace. Thus, it is clearly a necessity to introduce a blower to a modern furnace to maintain minimum desired efficiency standards.
Since the introduction of a blower increases the cost of the furnace, it is important to connect the blower assembly to the furnace in the most effective and efficient manner. There are currently two types of furnace blower motor assemblies sold on the market. The first type of blower motor assembly is known as the xe2x80x9cround exhaust/non-flush mount blower assemblyxe2x80x9d. The second type of blower motor assembly is known as the xe2x80x9crectangular exhaust/flush mount blower assemblyxe2x80x9d. While both types of blower motor assemblies accomplish the goal of an 80% efficiency standard, each type also has its own significant shortcomings addressed below, which are solved by the present invention.
The first type of blower assembly is the xe2x80x9cround exhaust/non-flush mount blower assemblyxe2x80x9d. This type of blower assembly has the advantage of having a round exhaust that is offset from the mounting surface. The round exhaust allows the furnace manufacturer to install the blower onto the furnace without adding an expensive transition piece to allow the customer to hook up their round flue pipe. A significant disadvantage of this blower is that the mounting flange is not flush with the mounting surface that connects with the furnace collector box.
The disadvantage with the mounting flange not being flush with the collector box lies in the steps required to mount the blower to a furnace. Great care must be taken when mounting the blower to the furnace because the mounting screws overhang and cocking of the blower during assembly can cause great damage if the process is not done correctly. If the blower is damaged, repair is expensive and time consuming and there are quality issues involved with the finished product. Therefore, because of the possible damages that can occur with improper mounting, the assembler must take greater care and work at a slower pace while ensuring that the screws are not over-torqued when securing the blower assembly to the furnace.
Other manufacturers have attempted to address this problem through the use of a mounting flange added as a third piece to their round exhaust/non-flush mounted blower assembly. A mounting flange addition provided a solution to the cocking problem but at an increased cost and complexity due to the exact dimensional requirements to mount the blower to the mounting flange and then the furnace.
The second type of blower motor assembly is known as the xe2x80x9crectangular exhaust/flush mount blower assemblyxe2x80x9d. This type of blower assembly has the advantage of flush mounting of the blower, thereby significantly removing the chance. that the blower is not flush during assembly and therefore preventing the damage that occurs when the blower is cocked. Flush mounting allows for a fast and worry-free mounting process without fear of damage and expensive reworking issues. Unfortunately, this type of blower assembly has the disadvantage of having a rectangular exhaust outlet. Therefore, to allow the customer to attach the blower assembly to a round exhaust flue, an expensive rectangular to round transition piece must be used. Typically, this transition device is formed from cast aluminum, which is expensive to manufacture.
An attempt to address this problem involved the use of a transition piece made out of a polymeric material. The polymer transition piece was either injection molded or thermoformed. A polymer transition piece has largely been discarded because of the inherent problems associated with the use of plastics in the harsh operating environment the transition piece must endure. Polymers that are able to withstand the harsh operating environment are very expensive, and even with the use of expensive engineering polymers, there still remain potential problems with polymer durability that has made the use of polymers a less than desirable solution.
The present invention solves the problems associated with the currently available furnace blower motor assemblies with a novel and cost efficient solution. There has been an unrecognized but long felt need in the industry to solve the problems stated above. The present invention solves the above stated problems with an easy to manufacture and assemble solution that has eluded manufacturers for, several years.
Accordingly, it is an object of the present invention to provide a flush mounted round flue exhaust inducer housing formed from a two-piece stamped steel shell. It is another object of the present invention to provide a blower housing that reduces the complexity involved with manufacturing. It is yet another object of the present invention to provide a simple cost effective solution to provide a flush mounted blower assembly with a round exhaust flue with a separate transition device.
The present invention relates to a blower housing formed from a two-piece construction of stamped steel members joined to each other. The blower housing includes an integrally formed transition section extending from a rectangular throat to a circular exhaust outlet and provides for flush mounting of the blower housing to a furnace. The blower housing includes a first housing member that includes a generally planar back plate. The back plate includes an inlet opening that allows flue gases to enter into the blower housing from the furnace. The first housing member includes an outer edge that terminates with an extended lip portion.
The first housing member defines the first portion of the outlet transition section between the impeller cavity and the circular exhaust outlet. The first housing member includes an attachment flange that extends along the integrally formed transition section.
The blower housing further includes a second housing member that is attachable to the first housing member to form the impeller cavity. The impeller cavity is sized to contain an impeller mounted to a motor shaft that extends through the top mounting portion of the second housing member. As the impeller rotates within the impeller cavity, a flow of exhaust gases is directed into the transition section and finally out of the exhaust outlet. The second housing member includes an outer wall that spaces the first housing member from the second housing member.
The second housing member defines the second half of the transition section and includes a flange that is received on a mating flange and lip of the first housing member.
The two-piece combination of the first housing member and the second housing member combine to create the transition section that extends between a circular exhaust outlet and the rectangular outlet throat of the impeller cavity formed in the blower housing. Thus, as the impeller rotates, exhaust gases pass through the outlet throat of the impeller cavity and enter into the transition section. The transition section is angled away from the back plate of the first housing member such that the exhaust outlet of the transition section permits flush mounting of the blower housing.
During construction, the first housing member and the second housing member can be joined by any one of several attachment methods. Preferably, the first housing member and the second housing member are formed from stamped steel and are joined by crimping the two members to each other. The crimping provides a tight connection that will resist rattling and is less labor intensive, thus reducing the cost to manufacture the blower housing of the present invention.